Sleep Calculator — Optimal Wake-Up Time Calculator

Find the best time to wake up or go to sleep based on 90-minute sleep cycles. Wake up feeling refreshed by timing your alarm to the end of a complete REM sleep cycle.

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Preparing your calculator

How to Use Sleep Calculator

  1. 1Enter the required values in the input fields above.
  2. 2Click the Calculate button or results update instantly as you type.
  3. 3View your results in the output panel below the inputs.
  4. 4Adjust any values to recalculate instantly.